<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>用户登录</title>
    <link rel="stylesheet" href="css/common.css">
    <link rel="stylesheet" href="css/login.css">
</head>
<body>
<!-- 导航栏 -->
<div class="nav">
    Chit-chat
</div>
<!-- 主窗口区 -->
<div class="login-container">
    <div class="login-dialog">
        <h3>登录</h3>
        <div class="row">
            <span>用户名</span>
            <input type="text" id="username">
        </div>
        <div class="row">
            <span>密码</span>
            <input type="password" id="password">
        </div>
        <div class="row">
            <button id="submit" onclick="login()">登录</button>
        </div>
    </div>
</div>

<!-- 引入 jquery -->
<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
<!-- 实现前后端交互的逻辑 -->
<script>

    function login(){
        if($("#username").val() == "" || $("#password").val() == ""){
            alert("用户名、密码不能为空!");
            return ;
        }
        $.ajax({
            type:"post",
            url: "/user/login",
            data: {
                username: $("#username").val(),
                password: $("#password").val()
            },
            success: function (result){
                if(result && result.id > 0){
                    alert("登录成功!");
                    location.href = "client.html";
                }else if (result && result.id == -1){
                    alert("用户已上线!")
                } else {
                    alert("登录失败，用户名或密码错误!");
                }
            }
        });
    }

</script>
</body>
</html>